Cleanse is always a good defence for ad carries, it removes most forms of CC as well as Exhaust and Ignite. However you can't take this advantage unless it's used at exactly the right point of time,
Take note of your opponent's abilities, what kind of CC do they have and what summoner spells do they have, be mentally prepared.
Don't cleanse every spell that hits you, only cleanse life threatening ones, such as Taric's stun before a gank. Don't use it to remove CC that is only intended to poke, such as Lux's snare when you have over 70% health and are not in danger of death.
If you see an incoming CC and you expect to receive it, place your finger over the F button and be ready to press it.